In many chemical plants and refineries where GHS products are noted , it has become routine to do hot work in process areas — often with the units still running. The current trend in our industry is to take the least amount of time possible to do maintenance work. Planned shutdowns and turnarounds for maintenance are held much less frequently than in the past. Even when such work is scheduled, the length of time allowed is enough to take care of only the most serious work orders.
But remember, it is almost always safer to move that piece of equipment out of the process area to a safe place before doing hot work on it.
Working in the HOT is not the same a HOT WORK PERMIT and what does your Policies a. Where hot work is permitted b. When hot work is permitted c. Who authorizes hot work.
And what about Procedures? a. What must be assessed before permitting/performing hot work in an area or on a process piece of equipment or area b. What to do to prepare an area for hot work c. What to do if hot work cannot be avoided in a particularly hazardous area d. What hot work tools are required e. How to obtain a hot work permit, when they are required, and who can administer them
A hot work permit is only as good as the information included on it and the skills of the person issuing it. Several factors have to be considered before issuing a permit:
Hot work obviously can’t be done near explosive atmospheres. The area should be checked with a combustible gas analyzer at different levels. Even if the air is clear, will it stay that way? Continuous monitoring should be standard practice.
Move combustible materials in the area 35 feet from the hot work area. If impractical, protect them with flame-proof covers or guards.
Fire protection equipment
Inspect all fire equipment and do not allow hot work in sprinklered buildings if that protection is impaired.
Safe condition of surrounding areas
If something is going on near a hot work area that could create a hazardous condition, those operations must be made safe until the hot work is finished. If there are floor openings, gratings, wall openings or open duct work or conveyors that could allow sparks from the hot work to be carried into another area, they must be covered or blocked.
What Is Hot Work and Why Is It Hazardous?
OSHA defines hot work as: “work involving electric or gas welding, cutting, brazing or similar flame or spark-producing operations.”
We should be concerned about hot work because:
• On plant sites a spark invites disaster because of the tremendous potential for flammable vapors or gases to be present.
• When we cut, weld or grind in our facilities, literally thousands of ignition sources in the form of sparks and hot slag are created.
• Sparks and slag can scatter throughout an area where hot work is going on — sometimes up to 35 feet or more.
• Sparks and slag can also pass through cracks, gratings, doors, drains, open hatches and other openings in walls, floors or vessels, creating fire/explosion hazards in sometimes distant areas.
Anything combustible or flammable can be ignited by hot work. Welding, cutting and brazing are pretty obvious; but what about those other “flame or spark-producing operations” that OSHA talks about?
• Grinding, sanding and sand blasting;
• Metal-on-metal contact, metal-on-concrete contact;
• Internal combustion engines;
• Electric tools, such as drills or saws;
• Cameras, battery-powered instruments, radios, etc.; and
• Even your clothing can cause static sparks.
•If your hot work permit system does not address these sources, it is not giving you the protection the law requires.
When you check out an area before doing hot work, it’s natural to focus on the hazards of the process (solvent vapors, flammable gases and explosive dust-in-air mixtures, etc.). But wait; it’s easy to overlook other combustible materials in a hot work area like grass, debris, trash, pallets and fiber drums. It pays to check the area out thoroughly.
Hot Work Terms and Definitions workers need to fully understand on yours sites in GHS chemicals.
Cad welding – a form of thermite welding used to bond wire to metal. Electrically Classified area – a location in which flammable gases or vapors are or may be present in the air in quantities sufficient to produce explosive or ignitable mixtures, which requires electrical equipment to be gas tight.
Combustible material – a substance that can be ignited and burned (e.g., cardboard boxes, filters, paper trash, ground cover like dry grass and brush, textiles, plastics, paper). Designated safe hot work area (non-permit-required area) – an area that is free of combustible and flammable materials and that is constructed of noncombustible or fire-resistant construction materials. A designated safe hot work area cannot be located in an electrically classified area. Fire watch – an individual assigned to monitor the hot work activity.
Flammable – capable of igniting easily, burning intensely or spreading flame rapidly. Greenfield – facilities and locations which have not contained hydrocarbon materials, and are not connected to an existing facility, equipment, or piping system that has contained hydrocarbon materials.
Hot tap – a technique of attaching connections, such as weld-o-let or split tees, to equipment in service by welding. Hot work – using tools and/or equipment that may create an arc, spark, or open flame (e.g., electric or gas welding, cutting, brazing, burning, grinding, use of an oxyacetylene torch, or similar operations, including manually lighting production equipment). Intrinsically Safe – equipment that is safe to use in an electrically classified area or a potentially hazardous area that may contain fuel in the atmosphere, such as flammable gasses or vapors, or combustible dust.
Lower Explosive Limit (LEL) – a concentration (lowest percentage of the substance in air) that will produce a flash of fire when an ignition source (such as heat, arc, or flame) is present. At concentrations lower than the LEL, the mixture is too lean to burn. Isolation – using one of the following methods to isolate piping or equipment: • Disconnected equipment with blind flange installed. • Full-thickness blind skillet with gaskets on the pressure side. • Spectacle blind with gaskets on the pressure side. • Use of a block valve in conjunction with Lockout/Tagout. Occupational Exposure Limits (OEL) – an 8-hour time weighted average exposure limit, designated by Your company.
Permissible Exposure Limit (PEL) – an 8-hour time weighted average exposure limit, designated and enforceable by the United States Occupational Safety and Health Administration. Permit Issuer – individual who has completed the required training and is authorized to write Hot Work Permits. Permit receiver – individual who has requested a Hot Work Permit, for work tasks that will be performed. Purge – remove the contents within pipe or equipment and replace it with another gas or liquid. Render inert – change the contents of an enclosure, vessel, or piping by using an inert substance (i.e., nitrogen or water) to render the atmosphere incapable of supporting combustion. Unclassified area – a location that is not electrically classified as a Class I, Division 1, or Division 2 area.
Move combustible materials at least 35 feet from the hot work area. If they can’t be moved, they must at least be protected with flame-proofed covers or shielded with guards or curtains. Edges of covers at the floor should be tight to prevent sparks from going under them. Combustible flooring should be wet down or protected by fire-resistant shields. Cover floor drains, trenches, sewer boxes, etc.
That fire watch person is CRITICAL just like the work being done prior!
A fire watch is someone who . . . well . . . watches!
He or she continuously monitors the hot work area for fires that may be caused by flying sparks and any changes in the surrounding conditions that may make the hot work unsafe. The key word here is continuously. This is not a job to be given to an operator or mechanic who already has another job to do.
A fire watch is well trained.
Fire watches must be trained in using fire-extinguishing equipment, including “hands on” practice with training fires. They must also be trained in the facility’s emergency procedures (i.e., sounding an alarm, evacuation routes, etc.) as outlined in the plant’s written emergency response plan.
A fire watch knows what to do and when to do it.
If a fire occurs, the fire watch must warn the hot work crew and sound the plant alarm. The fire watch may try to extinguish a fire only when it is obviously within the capacity of the fire extinguishing equipment available and only if the fire watch has been properly trained.
A fire watch must cover all areas where sparks might travel.
If there are floor or wall openings, open duct work, gratings, open sewer drains or any other way a spark may travel to another level or area, more personnel need to be assigned as fire watches.
It’s not over even when it’s over.
When the hot work ends, the fire watch must continue for at least another 30 minutes.*